China has no legal basis to claim “historic rights” to islands in the South China Sea, an international tribunal ruled on Tuesday in a bitter dispute that risks stoking further tensions in Southeast Asia.

“The Tribunal concluded that there was no legal basis for China to claim historic rights within the sea areas falling within the ‘nine-dash line’,” the Hague-based Permanent Court of Arbitration said in a statement.

The Philippines welcomed the ruling while urging restraint.